This adds bitops tests to the test_kasan module. In a follow-up patch,
support for bitops instrumentation will be added.
Signed-off-by: Marco Elver <[email protected]>
---
Changes in v3:
* Use kzalloc instead of kmalloc.
* Use sizeof(*bits).
Changes in v2:
* Use BITS_PER_LONG.
* Use heap allocated memory for test, as newer compilers (correctly)
warn on OOB stack access.
---
lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 72 insertions(+), 3 deletions(-)
diff --git a/lib/test_kasan.c b/lib/test_kasan.c
index 7de2702621dc..1ef9702327d2 100644
--- a/lib/test_kasan.c
+++ b/lib/test_kasan.c
@@ -11,16 +11,17 @@
#define pr_fmt(fmt) "kasan test: %s " fmt, __func__
+#include <linux/bitops.h>
#include <linux/delay.h>
+#include <linux/kasan.h>
#include <linux/kernel.h>
-#include <linux/mman.h>
#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/uaccess.h>
-#include <linux/module.h>
-#include <linux/kasan.h>
/*
* Note: test functions are marked noinline so that their names appear in
@@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
strnlen(ptr, 1);
}
+static noinline void __init kasan_bitops(void)
+{
+ long *bits = kzalloc(sizeof(*bits), GFP_KERNEL);
+ if (!bits)
+ return;
+
+ pr_info("within-bounds in set_bit");
+ set_bit(0, bits);
+
+ pr_info("within-bounds in set_bit");
+ set_bit(BITS_PER_LONG - 1, bits);
+
+ pr_info("out-of-bounds in set_bit\n");
+ set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __set_bit\n");
+ __set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in clear_bit\n");
+ clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __clear_bit\n");
+ __clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in clear_bit_unlock\n");
+ clear_bit_unlock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __clear_bit_unlock\n");
+ __clear_bit_unlock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in change_bit\n");
+ change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __change_bit\n");
+ __change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_set_bit\n");
+ test_and_set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_set_bit\n");
+ __test_and_set_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_set_bit_lock\n");
+ test_and_set_bit_lock(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_clear_bit\n");
+ test_and_clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_clear_bit\n");
+ __test_and_clear_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_and_change_bit\n");
+ test_and_change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in __test_and_change_bit\n");
+ __test_and_change_bit(BITS_PER_LONG, bits);
+
+ pr_info("out-of-bounds in test_bit\n");
+ (void)test_bit(BITS_PER_LONG, bits);
+
+#if defined(clear_bit_unlock_is_negative_byte)
+ pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
+ clear_bit_unlock_is_negative_byte(BITS_PER_LONG, bits);
+#endif
+ kfree(bits);
+}
+
static int __init kmalloc_tests_init(void)
{
/*
@@ -664,6 +732,7 @@ static int __init kmalloc_tests_init(void)
kasan_memchr();
kasan_memcmp();
kasan_strings();
+ kasan_bitops();
kasan_restore_multi_shot(multishot);
--
2.22.0.rc1.257.g3120a18244-goog
On Fri, May 31, 2019 at 05:08:29PM +0200, Marco Elver wrote:
> This adds bitops tests to the test_kasan module. In a follow-up patch,
> support for bitops instrumentation will be added.
>
> Signed-off-by: Marco Elver <[email protected]>
> ---
> Changes in v3:
> * Use kzalloc instead of kmalloc.
> * Use sizeof(*bits).
Thatnks for cleaning these up! FWIW:
Acked-by: Mark Rutland <[email protected]>
Mark.
>
> Changes in v2:
> * Use BITS_PER_LONG.
> * Use heap allocated memory for test, as newer compilers (correctly)
> warn on OOB stack access.
> ---
> lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 72 insertions(+), 3 deletions(-)
>
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index 7de2702621dc..1ef9702327d2 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -11,16 +11,17 @@
>
> #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
>
> +#include <linux/bitops.h>
> #include <linux/delay.h>
> +#include <linux/kasan.h>
> #include <linux/kernel.h>
> -#include <linux/mman.h>
> #include <linux/mm.h>
> +#include <linux/mman.h>
> +#include <linux/module.h>
> #include <linux/printk.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> #include <linux/uaccess.h>
> -#include <linux/module.h>
> -#include <linux/kasan.h>
>
> /*
> * Note: test functions are marked noinline so that their names appear in
> @@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
> strnlen(ptr, 1);
> }
>
> +static noinline void __init kasan_bitops(void)
> +{
> + long *bits = kzalloc(sizeof(*bits), GFP_KERNEL);
> + if (!bits)
> + return;
> +
> + pr_info("within-bounds in set_bit");
> + set_bit(0, bits);
> +
> + pr_info("within-bounds in set_bit");
> + set_bit(BITS_PER_LONG - 1, bits);
> +
> + pr_info("out-of-bounds in set_bit\n");
> + set_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __set_bit\n");
> + __set_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in clear_bit\n");
> + clear_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __clear_bit\n");
> + __clear_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in clear_bit_unlock\n");
> + clear_bit_unlock(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __clear_bit_unlock\n");
> + __clear_bit_unlock(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in change_bit\n");
> + change_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __change_bit\n");
> + __change_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in test_and_set_bit\n");
> + test_and_set_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __test_and_set_bit\n");
> + __test_and_set_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in test_and_set_bit_lock\n");
> + test_and_set_bit_lock(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in test_and_clear_bit\n");
> + test_and_clear_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __test_and_clear_bit\n");
> + __test_and_clear_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in test_and_change_bit\n");
> + test_and_change_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in __test_and_change_bit\n");
> + __test_and_change_bit(BITS_PER_LONG, bits);
> +
> + pr_info("out-of-bounds in test_bit\n");
> + (void)test_bit(BITS_PER_LONG, bits);
> +
> +#if defined(clear_bit_unlock_is_negative_byte)
> + pr_info("out-of-bounds in clear_bit_unlock_is_negative_byte\n");
> + clear_bit_unlock_is_negative_byte(BITS_PER_LONG, bits);
> +#endif
> + kfree(bits);
> +}
> +
> static int __init kmalloc_tests_init(void)
> {
> /*
> @@ -664,6 +732,7 @@ static int __init kmalloc_tests_init(void)
> kasan_memchr();
> kasan_memcmp();
> kasan_strings();
> + kasan_bitops();
>
> kasan_restore_multi_shot(multishot);
>
> --
> 2.22.0.rc1.257.g3120a18244-goog
>
Thanks, I've sent v4.
On Thu, 13 Jun 2019 at 12:49, Andrey Ryabinin <[email protected]> wrote:
>
>
>
> On 5/31/19 6:08 PM, Marco Elver wrote:
> > This adds bitops tests to the test_kasan module. In a follow-up patch,
> > support for bitops instrumentation will be added.
> >
> > Signed-off-by: Marco Elver <[email protected]>
> > ---
> > Changes in v3:
> > * Use kzalloc instead of kmalloc.
> > * Use sizeof(*bits).
> >
> > Changes in v2:
> > * Use BITS_PER_LONG.
> > * Use heap allocated memory for test, as newer compilers (correctly)
> > warn on OOB stack access.
> > ---
> > lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 72 insertions(+), 3 deletions(-)
> >
> > diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> > index 7de2702621dc..1ef9702327d2 100644
> > --- a/lib/test_kasan.c
> > +++ b/lib/test_kasan.c
> > @@ -11,16 +11,17 @@
> >
> > #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
> >
> > +#include <linux/bitops.h>
> > #include <linux/delay.h>
> > +#include <linux/kasan.h>
> > #include <linux/kernel.h>
> > -#include <linux/mman.h>
> > #include <linux/mm.h>
> > +#include <linux/mman.h>
> > +#include <linux/module.h>
> > #include <linux/printk.h>
> > #include <linux/slab.h>
> > #include <linux/string.h>
> > #include <linux/uaccess.h>
> > -#include <linux/module.h>
> > -#include <linux/kasan.h>
> >
> > /*
> > * Note: test functions are marked noinline so that their names appear in
> > @@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
> > strnlen(ptr, 1);
> > }
> >
> > +static noinline void __init kasan_bitops(void)
> > +{
> > + long *bits = kzalloc(sizeof(*bits), GFP_KERNEL);
>
> It would be safer to do kzalloc(sizeof(*bits) + 1, GFP_KERNEL) and change tests accordingly to: set_bit(BITS_PER_LONG + 1, bits) ...
> kmalloc will internally round up allocation to 16-bytes, so we won't be actually corrupting someone elses memory.
>
>
> > + if (!bits)
> > + return;
> > +
> > + pr_info("within-bounds in set_bit");
> > + set_bit(0, bits);
> > +
> > + pr_info("within-bounds in set_bit");
> > + set_bit(BITS_PER_LONG - 1, bits);
>
>
> I'd remove these two. There are plenty of within bounds set_bit() in the kernel so they are well tested already.
>
> --
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On 5/31/19 6:08 PM, Marco Elver wrote:
> This adds bitops tests to the test_kasan module. In a follow-up patch,
> support for bitops instrumentation will be added.
>
> Signed-off-by: Marco Elver <[email protected]>
> ---
> Changes in v3:
> * Use kzalloc instead of kmalloc.
> * Use sizeof(*bits).
>
> Changes in v2:
> * Use BITS_PER_LONG.
> * Use heap allocated memory for test, as newer compilers (correctly)
> warn on OOB stack access.
> ---
> lib/test_kasan.c | 75 ++++++++++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 72 insertions(+), 3 deletions(-)
>
> diff --git a/lib/test_kasan.c b/lib/test_kasan.c
> index 7de2702621dc..1ef9702327d2 100644
> --- a/lib/test_kasan.c
> +++ b/lib/test_kasan.c
> @@ -11,16 +11,17 @@
>
> #define pr_fmt(fmt) "kasan test: %s " fmt, __func__
>
> +#include <linux/bitops.h>
> #include <linux/delay.h>
> +#include <linux/kasan.h>
> #include <linux/kernel.h>
> -#include <linux/mman.h>
> #include <linux/mm.h>
> +#include <linux/mman.h>
> +#include <linux/module.h>
> #include <linux/printk.h>
> #include <linux/slab.h>
> #include <linux/string.h>
> #include <linux/uaccess.h>
> -#include <linux/module.h>
> -#include <linux/kasan.h>
>
> /*
> * Note: test functions are marked noinline so that their names appear in
> @@ -623,6 +624,73 @@ static noinline void __init kasan_strings(void)
> strnlen(ptr, 1);
> }
>
> +static noinline void __init kasan_bitops(void)
> +{
> + long *bits = kzalloc(sizeof(*bits), GFP_KERNEL);
It would be safer to do kzalloc(sizeof(*bits) + 1, GFP_KERNEL) and change tests accordingly to: set_bit(BITS_PER_LONG + 1, bits) ...
kmalloc will internally round up allocation to 16-bytes, so we won't be actually corrupting someone elses memory.
> + if (!bits)
> + return;
> +
> + pr_info("within-bounds in set_bit");
> + set_bit(0, bits);
> +
> + pr_info("within-bounds in set_bit");
> + set_bit(BITS_PER_LONG - 1, bits);
I'd remove these two. There are plenty of within bounds set_bit() in the kernel so they are well tested already.